Index: tests/OFArrayTests.m
==================================================================
--- tests/OFArrayTests.m
+++ tests/OFArrayTests.m
@@ -223,12 +223,15 @@
 
 	ok = false;
 	i = 0;
 	@try {
 		for (OFString *s in m[0]) {
+			(void)s;
+
 			if (i == 0)
 				[m[0] addObject: @""];
+
 			i++;
 		}
 	} @catch (OFEnumerationMutationException *e) {
 		ok = true;
 	}

Index: tests/OFDictionaryTests.m
==================================================================
--- tests/OFDictionaryTests.m
+++ tests/OFDictionaryTests.m
@@ -111,13 +111,16 @@
 
 	TEST(@"Fast Enumeration", ok)
 
 	ok = false;
 	@try {
-		for (OFString *key in dict)
+		for (OFString *key in dict) {
+			(void)key;
+
 			[dict setObject: @""
 				 forKey: @""];
+		}
 	} @catch (OFEnumerationMutationException *e) {
 		ok = true;
 	}
 
 	TEST(@"Detection of mutation during Fast Enumeration", ok)

Index: tests/OFListTests.m
==================================================================
--- tests/OFListTests.m
+++ tests/OFListTests.m
@@ -141,12 +141,15 @@
 
 	TEST(@"Fast Enumeration", ok)
 
 	ok = false;
 	@try {
-		for (OFString *obj in list)
+		for (OFString *obj in list) {
+			(void)obj;
+
 			[list removeListObject: [list lastListObject]];
+		}
 	} @catch (OFEnumerationMutationException *e) {
 		ok = true;
 	}
 
 	TEST(@"Detection of mutation during Fast Enumeration", ok)